When a signal of user equipment has been subjected to severe interference or deep attenuation, the user equipment may undergo a radio link failure. The radio link failure will result in interruption of service transmission, during which the user equipment can not transmit or receive any data service. Further, a too long time of interruption of connection will produce a negative effect on an application layer, thereby lowering user experience.
In order to account for amount of mobile data which increases exponentially in a network, small cells are deployed in hot regions in a heterogeneous network. Standardization work of 3GPP LTE Release 12 mainly focuses on small cell enhancement (SCE). As compared with the traditional heterogeneous network, a larger number of small cells will be deployed in a small cell network (SCN). SCN is not a coverage-limited network, but the user equipment in the small cells will subject to severe interference from neighboring nodes due to the dense deployment of the small cells, and thus the radio link failure will occur more easily. Therefore, in order to provide stable service for users, a solution which quickly solves the radio link problem for SCN is required.
Existing quick solutions with respect to the radio link problem in the heterogeneous network mainly include two directions: (1) a time length of a T310 timer is reduced to reduce service interruption time of the user equipment, in which the T310 timer is defined as being triggered when the user equipment deems the radio link problem has been detected and as being expired when the user equipment declares the radio link failure; and (2) radio resource control (RRC) connection is re-established according to user equipment context by a network end. Regarding solution (1), it may directly reduce an overall service interruption time, but might cause the user equipment to declare the radio link failure too early, that is, might make the user equipment lose an opportunity to wait for recovering of a radio link in which a problem has occurred, which may possibly increase the service interruption time to some extent. As for solution (2), it can improve probability of succeeding in reestablishment of RRC connection, but needs additional signaling overhead for transmitting new user equipment context when the user equipment context saved in a source cell has changed, the signaling overhead being in proportional to number of potential target cells for which the RRC connection is reestablished, and thus it might introduce additional time delay.